The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Referring now to FIG. 1, a functional block diagram of an engine system 100 is presented. Air is drawn into an engine 102 through an intake manifold 104. A throttle valve 106 varies airflow into the intake manifold 104. An electronic throttle controller (ETC) 108 actuates the throttle valve 106, thereby controlling opening of the throttle valve 106.
The air mixes with fuel provided by a fuel injector 110 to form an air and fuel mixture. The air/fuel mixture is combusted within cylinders of the engine 102, such as cylinder 112. Combustion may be initiated by, for example, a spark from a spark plug 114. Exhaust gas resulting from combustion is expelled from the cylinder 112 to an exhaust system 116. Combustion of the air/fuel mixture generates torque.
An engine control module (ECM) 130 controls torque output by the engine 102. For example, the ECM 130 adjusts torque output by the engine by adjusting the opening of the throttle valve 106, the amount of fuel injected by the fuel injector 110, and/or the timing of the spark provided by the spark plug 114.
The ECM 130 may adjust the torque output by the engine 102 based on signals provided by various sensors that measure various engine parameters at locations throughout the engine system 100. For example, the ECM 130 receives signals from other sensors 132, which may include, an intake air temperature (IAT) sensor, a mass air flow (MAF) sensor, a manifold absolute pressure (MAP) sensor, an engine coolant temperature sensor (ECT), an oil temperature sensor (OT) and/or any other suitable sensor. Additionally, the ECM 130 may adjust torque output by the engine 102 based on a humidity signal from a humidity sensor 134 that measures humidity of air. For example only, the humidity sensor 134 measures humidity of the air drawn into the engine 102.